The *real* FAQ for your site should live [here](http://meta.serverfault.com/questions/tagged/faq) - and you should populate it with *whatever* questions come up frequently, ideally by transforming one instance. If you can't easily close common questions as duplicates of FAQ entries, there's a problem. 

It's actually kinda shocking that you're suggesting a *long-form* site FAQ when there are only 6 questions in the meta FAQ - if something isn't covered (or is buried within an existing but overly-broad FAQ question), then it should be there *first*. 

If you find yourself referencing a particular FAQ excessively, *then* it might be time to think about featuring it more prominently in the site FAQ.